The Phase I research will evaluate the feasibility of using time-of-flight secondary ion mass spectrometry (TOF-SIMS) to provide sensitive and structurally significant characterization of the surface composition of biological membranes. The research will analyze a variety of model membrane systems in order to fully evaluate this feasibility. The data produced in this study will be evaluated specifically with regard to its diagnostic value in elucidation membrane chemical structure. The long term objective of this research is to develop routine, quantitative surface analysis techniques for the chemical analysis of membrane surfaces. The achievement of this objective could find extensive application in a variety of biological sciences including synthetic membrane development, fundamental investigations of membrane structure/function relationships and possibly, better understanding of the role biomembranes play in the state of health of organisms.